A presença de substâncias húmicas na água de abastecimento tem recebido a atenção de diversos pesquisadores nas últimas décadas, pois pode gerar subprodutos ao ser exposta a agentes oxidantes e desinfetantes. A filtração em múltiplas etapas (FiME) se apresenta como uma alternativa para realizar o tratamento de água de comunidades de pequeno porte, entretanto, a eficiência quanto à remoção de cor verdadeira associada ao carbono orgânico dissolvido ou às substâncias húmicas, tem sido questionada ou relatada como baixa. A filtração lenta com pré-ozonização vem sendo utilizada, pois o ozônio atua nas moléculas da matéria orgânica, aumentando sua biodegradabilidade e seus subprodutos desaparecem logo após a aplicação. A aplicação conjunta do ozônio e peróxido de hidrogênio, tem o objetivo de produzir espécies com radicais livres, de vida curta, que sejam altamente reativos e possam oxidar a maior parte das substâncias presentes na água natural. A presente pesquisa avaliou a remoção de substâncias húmicas na filtração lenta, utilizando para essa avaliação parâmetros indiretos como cor verdadeira, absorvância 254 nm e carbono orgânico dissolvido. Foram realizados cinco ensaios utilizando quatro filtros lentos, sendo dois com camada de carvão ativado granular (CAG), em que foram ensaiadas várias alternativas de pré-oxidação com ozônio e peróxido de hidrogênio. Obteve-se, como principal conclusão, que os filtros lentos com CAG, precedidos de oxidação com ozônio e depois peróxido de hidrogênio, em dosagens adequadas, apresentaram remoção média de cor verdadeira de 64% da cor inicial. Concluiu-se, também, que o peróxido de hidrogênio afeta o desenvolvimento da camada biológica, interferindo no desenvolvimento da perda de carga, na remoção de turbidez e na remoção de substâncias húmicas. / The presence of humic substances in the water of supply has been received attention of several researchers in the last decades, because it can generate by-products when being exposed to oxidants and disinfectant. The multistage filtration (FiME) is an alternative considered to achieve water treatment for small size rural communities, however, the efficiency with relationship to the removal of true color associated to the dissolved organic carbon or to the humic substances, it has been questioned or reported as low. The slow filtration with pre-ozonation is being used, since the ozone acted in the molecules of the organic matter of high molecular weight, increasing its biodegradability and by-products disappear soon after the application. The combined application of the ozone and hydrogen peroxide have the objective of producing species with free radicals, of short-lived, that are highly reagents and can oxidize most of the present substances in the natural water. The present research it evaluated the removal of humic substances in the slow sand filtration, using for that evaluation indirect parameters as true color, absorbance 254 nm and dissolved organic carbon. Five experiments were realized using four slow filters, being two with layer of activated carbon to granulate (CAG), in that several pre-oxidation alternatives were rehearsed with ozone and peróxido of hydrogen. It was obtained, as main conclusion that the slow filters with CAG preceded ofoxidation with ozone and hydrogen peroxide, in appropriate dosagens, presented medium removal of true color of 64% of the initial color. It was also concludes that the hydrogen peroxide interferes the development of the biological layer, interfering in the development of the loss of head, in the turbidity removal and in the removal of humic substances.

Orientador: Marcelo Cristianini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T13:21:34Z (GMT). No. of bitstreams: 1 Cavalcante_DanielAugusto_D.pdf: 1728563 bytes, checksum: 5b1a221ac77adab02aa5448549adb1b0 (MD5) Previous issue date: 2012 / Resumo: O leite, por ser um alimento nutritivo e completo, é altamente consumido em todo o mundo, tanto na sua ingestão direta como através de seus derivados. Muitas ações são colocadas em prática para garantir sua qualidade, desde cuidados com a saúde dos animais leiteiros até a utilização de tratamentos para garantir uma maior vida de prateleira dos produtos lácteos. O ozônio por estar sendo estudado, atualmente, na indústria de alimentos, e, por ser um produto utilizado nas formas líquida e gasosa foi o sanitizante utilizado para a efetivação dos experimentos. O presente estudo buscou avaliar a eficiência da aplicação do ozônio na indústria de laticínios, analisando suas características frente à: desinfecção da pele do teto das vacas antes da ordenha, inativação microbiana no leite in natura, aumento na estabilidade de queijo minas frescal e sanitização de equipamentos e ar ambiente de câmaras frigoríficas de estocagem de queijo minas frescal. Foi utilizado o sanitizante na forma líquida (água ozonizada), na concentração de 2,0mg.L-1, para os estudos de sanitização da pele do teto das vacas e para imersão do queijo minas frescal; e na forma gasosa para borbulhamento no leite e para sanitização da câmara fria, nas concentrações de 1,5 e 0,03 mg.L-1, respectivamente. Foi realizado delineamento inteiramente casualizado e os dados foram avaliados quanto à normalidade dos resíduos e homogeneidade das variâncias. Os microrganismos aeróbios mesófilos e Staphylococcus sp. na pele do teto das vacas apresentaram reduções de 2,36 e 2,03 ciclos logarítmicos, para clorexidina e 2,52 e 1,99 ciclos logarítmicos para a água ozonizada, respectivamente. Para estes tratamentos não foi verificado diferenças estatísticas significativas (P>0,05). As enterobactérias apresentaram reduções de 1,16 e 1,50 ciclos logarítmicos para a clorexidina (sanitizante utilizado para fins de comparação) e água ozonizada, sendo que estes resultados foram significativamente diferentes para P<0,05. A utilização do ozônio, na concentração de 1,5mg.L-1, no tempo de exposição de 15 minutos, apresentou reduções de 0,61; 0,97; 0,13; 1,04 e 0,48 ciclos logarítmicos, respectivamente, para os microrganismos aeróbios mesófilos, psicotróficos, enterobactérias e Staphylococcus sp.e bolores e levedura no leite in natura. Não foi observada a presença de enterobactérias, coliformes totais e termotolerantes e Staphylococcus sp., nas amostras de queijo minas frescal analisadas. As reduções decimais para as populações de aeróbios mesófilos, bactérias lácticas e bolores e leveduras em queijo minas frescal, imediatamente após a aplicação da água ozonizada na concentração de 2,0mg.L-1, durante 2 minutos foi de 1,53, 1,90 e 2,34 ciclos logaritmos, respectivamente; Observou-se uma redução de microrganismos aeróbios mesófilos e bolores e leveduras de 0,81 e 1,01 ciclos logarítmicos, respectivamente, no ar ambiente da câmara fria de estocagem de queijo minas frescal, após a aplicação do gás ozônio na concentração de 0,03 mg.L-1 / Abstract: Milk, as a complete and nutritious food, is highly consumed worldwide, both in its direct ingestion and through its derivatives. Many actions are put into practice to ensure its quality, since health care of the dairy cattle to the use of treatments to ensure a longer shelf life of dairy products. Ozone has been studied nowadays in the food industry and was used in liquid and gaseous forms as sanitizer for the experiments described here. This study tried to evaluate the effectiveness of ozone application in the dairy industry, analyzing its characteristics according to: the teat skin disinfection before milking the cows, microbial inactivation in raw milk, stability increase of minas frescal cheese, equipment, maturation and cold-storage sanitizing. The sanitizer was used in liquid form (ozonated water) at a concentration of 2.0 mg L-1 for the teat skin sanitizing studies and to immerse the minas frescal cheese; and gaseous form for bubbling milk and cold chamber sanitizing, at concentrations of 1.5 and 0.03 mg L-1, respectively. It was considered completely randomized design and the data were evaluated for normality of residuals and homogeneity of variances. The mesophilic aerobic microorganisms and Staphylococcus sp. on the teat skin had reductions of 2.36 and 2.03 logarithmic cycles, for chlorhexidine and 2.52 and 1.99 log-cycles for ozonated water, respectively. For these treatments, statistically significant differences were not observed (P> 0.05). The Enterobacteriacea had reductions of 1.16 and 1.50 logarithmic cycles for chlorhexidine and ozonated water, and these treatments showed statistically significant differences (P<0.05). The ozone sanitizer at a concentration of 1.5 mg L-1and exposure time of 15 minutes showed reductions of 0.61, 0.97, 0.13, 1.04 and 0.48 logarithmic cycles, respectively, for the mesophilic aerobic microorganisms, psychotropic, Enterobacteriaceae and Staphylococcusp., molds and yeast in the raw milk. We did not observe the presence of Enterobacteriaceae, total coliforms, thermotolerants and Staphylococcus spp. in the minas frescal cheese samples analyzed. The decimal reductions for the populations of aerobic mesophiles,lactic bacteria, yeasts and molds in the minas frescal cheese, immediately after the application of ozonated water at a concentration of 2.0 mg.L-1 for 2 minutes were 1, 53, 1.90 and 2.34 log-cycles, respectively. There was a reduction of mesophilic aerobic, yeast and mold of 0.81 and 1.01 log-cycles, respectively, in the minas frescal cheese cold storage and maturation, after application of ozone gas concentration of 0.03 mg.L-1 / Doutorado / Tecnologia de Alimentos / Doutor em Tecnologia de Alimentos

Orientador: José Antenor Pomílio / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-21T11:27:09Z (GMT). No. of bitstreams: 1 Rodrigues_DiegoTardivo_M.pdf: 3096616 bytes, checksum: 2d3b90e8f78bbfc91209e0e523c0f21b (MD5) Previous issue date: 2012 / Resumo: O trabalho tem como aplicação a geração de ozônio, que se dá em uma célula ozonizadora a partir de descargas eletrostáticas resultantes da aplicação de alta tensão por um transformador. Uma ressonância série essencialmente determinada pela indutância de dispersão e a capacitância equivalente do sistema surge, para este caso, em frequências na ordem de kHz. A operação do inversor de alimentação com uma frequência de chaveamento pouco maior do que a frequência de ressonância série tem como vantagens a comutação suave das chaves do inversor, um alto ganho de tensão e a possibilidade da construção de transformadores menores comparado à operação em 60 Hz. Visando o aumento da potência total do sistema e, consequentemente, aumento na capacidade de geração de ozônio, como alternativa para tal é feita a conexão em paralelo de diversos conjuntos formados por transformadora e respectiva célula, com potência da ordem de centenas de Watts, sendo estes alimentados por um único inversor. No entanto, a dispersão de parâmetros dos transformadores e células, leva a diferentes valores de potência por conjunto, estando alguns com potência acima da nominal e outros abaixo. A fim de se obter uma distribuição igual de potência entre as cargas, é apresentada uma estratégia para a equalização de potência em uma associação em paralelo de circuitos ressonantes com dispersão de parâmetros. O ajuste da sintonia é feito por meio de compensação série utilizando a técnica de síntese direta de reatâncias. Um modelo baseado no método médio generalizado foi obtido para que os parâmetros do controlador utilizado na equalização de potência fossem determinados. O uso de transformadores geralmente traz a necessidade de se precaver a um processo de saturação, todavia, é apresentada uma estratégia de controle capaz de impedir a saturação, por meio da síntese de capacitância variável série. Resultados de simulação e experimentais mostram o comportamento dos circuitos e das estratégias de controle propostas / Abstract: The work is applied to ozone generator, which occurs in an ozone generator cell through electrostatic discharges produced by high voltage transformer. A series resonance essentially determined by the leakage inductance and equivalent capacitance of the system arises in this case, at frequencies on the order of kHz. The operation of the inverter which feeds the load with switching frequency above the series resonance frequency has the advantages of soft switching at the inverter switches, a high voltage gain and the possibility of construct smaller transformers compared to operation at 60 Hz. Seeking to increase the total power system and, consequently, the capacity of ozone generation as an alternative is placed in parallel several loads formed by the transformer and respective cell, with a power of hundreds of Watts, fed by a single inverter. However, due to electrical parameters dispersion, there is not an equal distribution of power among the loads, with some being above the nominal power and other below. Order to obtain an equal distribution of power, a strategy is presented for balancing the power among paralleled loads. The balance is achieved through series compensation using the Direct Reactance Synthesis. A model based on the generalized average method is obtained for the controller parameters used in the equalization of power were found. Transformers usually need attention to avoid saturation; therefore, this work presents a control strategy to prevent the saturation, by synthesis of series variable capacitance. Simulation and experimental results show the behavior of circuits and proposed control strategies / Mestrado / Energia Eletrica / Mestre em Engenharia Elétrica

Orientador: Wilson de Figueiredo Jardim / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil / Made available in DSpace on 2018-08-01T21:14:54Z (GMT). No. of bitstreams: 1 Teixeira_ClaudiaPolideAlmeidaBarea_D.pdf: 9723868 bytes, checksum: af66f37d0f1ef9ed84d053f79363e4df (MD5) Previous issue date: 2002 / Resumo: Estudou-se a degradação de fenol em soluções preparadas em laboratório utilizando Processos Oxidativos Avançados (POA) que combinam Ti02, H202, 03, reagente de Fenton e UV. Os ensaios foram realizados utilizando um reator fotoquímico modelo Advantage 12 (Trojan) e a eficiência da mineralização dos compostos orgânicos presentes foi monitorada pela análise de COD (Carbono Orgânico Dissolvido). Observou-se que a maioria dos oxidantes testados se mostrou ineficazes na degradação de fenol quando utilizados em separado ou mesmo de forma combinada, sem a presença da radiação UV. O uso combinado de H2O2/UV se mostrou eficaz na degradação de soluções de fenol com CCOD = 100 mg.L-1 e a relação CH20/CCOD = 6/1 foi a mais eficiente para esta concentração de feno!. Neste caso os valores de EE/O variaram entre 23,5 e 34,7 kWh.m-3 e os valores de degradação entre 188 e 299 mgC.h-1. A vazão de recirculação da solução dentro do reator fotoquímico influencia a sua hidrodinâmica e, conseqüentemente, a eficiência do processo de degradação dos compostos orgânicos presentes. Para o reator utilizado, os melhores resultados foram obtidos com a vazão de 22 L.min-1 para os sistemas homogêneos e de 8 L.min-1 para os sistemas heterogêneos. Sistema de tratamento em batelada, utilizando um volume de solução variando entre 3 a 10 vezes o volume do reator se mostrou adequada para avaliar a tratabilidade dos efluentes e teve comportamento semelhante à utilização de sistemas com alimentação contínua. Os estudos de caso com diferentes efluentes industriais, apresentados no anexo, mostram que os POA são uma alternativa de tratamento para efluentes cujo tratamento convencional não seja possível ou mesmo adequado, como aqueles contendo compostos tóxicos, recalcitrantes, misturas complexas e/ou muito concentradas / Abstract: The degradation of phenol solutions was studies using AOP (Advanced Oxidation Processes) in the presence of Ti02, H2O2, 03, Fenton's reagent and UV. Experimental tests were performed using a photochemical reactor Advantage 12 (Trojan) and the efficiency was monitored by DOC (dissolved Organic Carbon) analysis. It was observed that the use of one oxidant alone yielded low mineralization rates, the same observed for the vast majority of combined oxidants. The use ofH202/UV showed higher efficiency in the degradation of 100 mgC.L-1 phenol solutions in the ratio CH20/CCOD = 6/1. Under this condition, values of EE/O between 23,5 and 34,7 kWh.m-3 and degradation rates between 188 and 299 mgC.h-1 were obtained. The recirculation flow rate used in the experiments control the reactor hydrodynamic and the quantum efficiency. Using this reactor, better results were obtained with 22 L.min-l to the homogeneous systems and 8 L.min-l to the heterogeneous systems. The utilization of batch systems using a total volume of3 up to 10 times the volume of the reactor showed to be valid in terms to evaluate the treatability of the effluents, yielding similar results to the ones obtained under continuous flow. Experiments with different industrial eft1uents presented as Case Studies show that AOPs are an alternative viable option to wastewater treatment, specially when conventional alternatives showed poor performance, such as in the ones containing toxic compounds, recalcitrant, complex mixtures and/or very concentrated solutions / Doutorado / Saneamento e Ambiente / Doutor em Engenharia Civil

[pt] O impacto dos pesticidas sobre a qualidade das águas subterrâneas tem sido objeto de preocupação de cientistas e autoridades públicas do nosso planeta. O uso intensivo de pesticidas na agricultura e a alta persistência de muitos deles tem requerido um rigoroso controle para evitar possíveis contaminações das águas subterrâneas e superficiais. O herbicida atrazina é um poluente freqüentemente encontrado nas águas subterrâneas em muitos países e foi selecionado para este estudo. O objetivo principal deste trabalho foi avaliar a efetividade, em escala de laboratório, da remediação de águas subterrâneas contaminadas com atrazina a partir do tratamento com ozônio produzido eletroquimicamente in situ. O anodo de β-PbO2 foi empregado na produção do ozônio por via eletroquímica e foi obtido por eletrodeposição sobre um substrato de titânio. A análise do depósito de PbO2 pela técnica de difração de raios-X confirmou apenas a presença das fases α e β do PbO2 e apontou a fase β como a principal. Foi comprovado que o aumento da corrente elétrica aumenta a taxa de produção de ozônio. Taxas de produção de O3 de 4,4; 19,5 e 39,1 mg h(-1) foram obtidas a partir de valores de densidades de correntes de 0,5, 1,0 e 1,5 kA m(-2),respectivamente. Os experimentos de degradação em batelada de uma solução de atrazina com concentração igual a 1 mg L(-1) para densidades de corrente de 0,5, 1 e 1,5 kA m(−2) mostraram que, com o aumento da densidade da corrente ocorreu um acréscimo na taxa de degradação da atrazina. Isto indica que o maior poder de oxidação do anodo, na medida em que se incrementa a corrente aplicada, é devido à maior eletrogeração dos oxidantes O3/.OH. A partir da análise cinética dos resultados obtidos nos experimentos de degradação foram obtidas boas correlações lineares quando os dados foram ajustados seguindo um modelo de pseudo-primeira ordem. As constantes cinéticas de pseudo- primeira ordem calculadas foram 6,2×10(−3), 8,8×10(−3) e 1,21×10(−2) min (−1) para 0,5, 1 e 1,5 kA m(−2), respectivamente. Os experimentos de degradação de atrazina em fluxo contínuo foram realizados numa coluna de acrílico de forma cilíndrica (26 cm x 4cm DI) preenchida com areia lavada, simulando o material do aqüífero, contendo um anodo de Ti/β-PbO2 e um catodo de Ti/RuO2. Durante os experimentos houve uma diminuição progressiva da concentração de atrazina no efluente de saída da coluna. Após 8 horas, as concentrações de atrazina na saída da coluna foram 75% e 80% menores do que a concentração de atrazina na entrada da coluna quando se aplicaram correntes de 0,4 e 0,6 A, respectivamente. Estes resultados confirmam a potencial aplicação deste tipo de estratégia de controle de plumas de contaminação e proporciona as bases para o desenvolvimento futuro desta técnica de remediação de aqüíferos. / [en] The impact of pesticides on the quality of groundwater has been the subject of scientific and public health concerns in the entire planet, especially in areas where groundwater is mainly used for human consumption. The intensive use of pesticides in agriculture and the high persistence of several of these chemicals have required a rigorous control of possible environmental contaminations, especially of drinking water sources. The herbicide atrazine is frequently detected in natural waters of many countries and was selected for investigation. A laboratory scale study on the evaluation of the effectiveness of remediation of atrazine in groundwater utilizing in situ electrochemical generated ozone was conducted. β-PbO2 was used as anode for ozone generation. β-PbO2 electrodes were prepared by electrodeposition on Ti plates. X-ray diffraction analysis confirmed that the deposit contained only the α and β PbO2 with the β phase prevailing. The electrochemical ozone production increases with incrementing the current density. The rate of ozone production during the electrolysis was 4.4, 19.5 and 39.1 mg h-1 for current densities of 0.5, 1.0 and 1.50 kAm(-2), respectively. In the experiments of atrazine degradation by electrochemically generated ozone a difference in atrazine degradation was found when the applied current density was varied. The results evidenced that the atrazine degradation rates increased with augmenting the current density. This is indicative of a greater oxidation ability of the anode with increasing the current applied due to the production of more electrogenerated active oxidant (O3/.OH). The kinetic analysis of the above results related to different reaction orders gave good linear correlations when the data was fitted with a pseudo first-order reaction rate equation. The pseudo first-order rate constants obtained were 6.2×10(−3), 8.8×10(−3), and 1.21×10(−2) min(−1) for 0.5, 0.1, and 1.5 kA m(−2), respectively. The acrylic column (26 cm x 4 cm ID) used in flow degradation experiments was packed with clean sand and contained a single set of electrodes. Two expanded titanium mesh coated with β-PbO2 and RuO2 served as anode and cathode, respectively. During the experiments the atrazine effluent concentration progressively diminished. After 8 hours of electrolysis the effluent atrazine concentration was reduced by 75% and 80% applying current densities of 0.4 and 0.6, respectively. These results confirm the potential applicability of this type of groundwater plume control strategy. The study constitutes a foundation to the future developing of this aquifer remediation technique.

Les pommiers sont la cible de nombreux ravageurs et maladies fongiques, à l’origine de pertes économiques importantes. Les agriculteurs sont dans l’obligation de traiter les micro-organismes responsables des maladies fongiques, notamment à l’aide de pesticides. Les produits phytosanitaires sont aujourd’hui très controversés. Ainsi, les pouvoirs publics, français et européens, contrôlent leur emploi par de nombreuses règlementations. Par conséquent, il apparaît nécessaire de proposer une alternative peu rémanente permettant de contrôler le développement fongique. L’objectif de cette thèse est d’évaluer l’efficacité d’une alternative innovante basée sur l’emploi d’eau chargée en ozone contre quatre espèces fongiques à l’origine des principales maladies du pommier : Venturia inaequalis, Botrytis cinerea, Neofabraea alba et Phytophthora syringae. Dans un premier temps, ce travail de thèse a permis de vérifier l’action anti-fongique de l’ozone sur les suspensions de spores des quatre espèces fongiques ainsi que sur différents stades de développement des spores de V.inaequalis. Il a été mis en évidence une différence de sensibilité selon l’espèce et le stade de développement considérés. Par ailleurs, l’altération de la membrane sous l’action de l’ozone a été observée par plusieurs expérimentations : quantification du degré de peroxydation des phospholipides membranaires, observations des spores au Microscope Electronique à Balayage et au Microscope Optique après colorations. Dans un second temps, l’effet de l’eau chargée en ozone a été évalué sur des jeunes plants de pommiers préalablement contaminés par les spores de V.inaequalis. Cette étude a confirmé l’action anti-fongique de l’eau chargée en ozone. Il a également été observé l’importance des quantités d’eau et d’ozone apportées qui doivent être maîtrisées pour optimiser l’efficacité du traitement. Ces résultats permettent de valider la candidature de l’ozone comme fongicide alternatif à l’emploi de produits phytosanitaires. Les modalités d’application devront faire l’objet de recherches supplémentaires en vue du transfert de la technologie du laboratoire au verger. / Apple trees are the target of a lot of pests and fungal diseases, responsible for many economic losses. Farmers treat these micro-organisms mainly with pesticides. Plant-protection products are today very controversial. French and European authorities control their use by means of numerous regulations. Therefore, an alternative solution with a low remanence must be found in order to limit fungal diseases. The aim of this thesis is to evaluate the innovative process efficiency based on the use of ozonated water against four fungal species: Venturia inaequalis, Botrytis cinerea, Neofabraea alba and Phytophthora syringae. Firstly, this work of thesis verified the ozone antifungal action on spores suspensions of the four fungal species and on different stages of development of V.inaequalis spores. According to the species and stages of development considered, a difference of sensibility was detected. Moreover, alteration of the membrane, due to ozone action, was observed thanks to several experimentations: quantification of phospholipids peroxidation, spore observations with Scanning Electron Microscopy and with Optical Microscopy after staining. Secondly, the ozonated water effects on seedlings previously contaminated by V.inaequalis spores were evaluated. This study confirmed the anti-fungal action of water containing ozone. It was also observed the importance of the water and of ozone quantities supplied. These quantities must be controlled to optimize the antifungal action of the treatment. These results validated the ozone application as a fungicide alternative of use of pesticides. Additional researches will be made concerning the treatment modalities: the aim is to transfer the technology from the laboratory to the orchard.

Mars is the fourth planet of the Solar System starting from the Sun. Compared to Earth, Mars has an atmosphere that is significantly thinner and undergoes also a seasonal cycle that is more marked. A Martian year lasts about two terrestrial years. One of the particularity of the Martian atmosphere is the continuous presence of an airborne dust layer.SPICAM is an instrument on board the Mars-Express satellite orbiting around Mars since the end of 2003. This instrument is divided in two modules: SPICAM/IR, a infrared spectrometer (1.0 - 1.7 µm) and SPICAM/UV, a spectrometer working in the ultraviolet range (106 - 317 nm). In this work, we have analysed the SPICAM/UV measurements that have been recorded in nadir viewing and in the spectral interval between 220 and 290 nm.The analysis of this spectral domain allows to study different species and constituents of the Martian atmosphere such as ozone, dust and ice clouds. In the frame of this work, we have developed a method capable of inverting the SPICAM spectra obtained in nadir viewing in order to simultaneously retrieve the integrated quantities of these different species i.e. the ozone total column, and the integrated optical depths of dust and ice clouds. The method is based on a radiative transfer code that allows to take into account the scattering of light by the different molecules and aerosols of the Martian atmosphere. The surface reflectivity is also considered and is retrieved in the cases where no ice clouds are present in the observed scenes, ice clouds reducing the sensitivity in the surface albedo. Therefore, a cloud detection algorithm has been developed and its results were compared with results obtained with other methods and instruments for validation.Our method has been used to invert the data measured by SPICAM/UV over more than four Martian years which allowed to obtain climatologies of the different studied species: the spatial and seasonal distributions of the ozone column, the optical depths of dust and ice clouds and also the surface albedo are presented in this work. These distributions are discussed and compared to those obtained in previous works obtained with other instruments.This work is also a preparation for the future measurement analysis of the NOMAD/UVIS, an instrument that will be on board the ExoMars Trace Gas Orbiter which is planned to be launched in the beginning of 2016. The algorithm developed in this thesis has also been used to assess performances of NOMAD/UVIS such as the detection limits of particular gases (O3, SO2 et NH3) and the values of the signal-to-noise ratio. / Mars est la quatrième planète du Système Solaire en partant du Soleil. Comparée à la Terre, Mars se caractérise par une atmosphère significativement plus ténue, et possède également un cycle annuel des saisons plus marqué. Une année martienne dure environ deux années terrestres. Une des particularités de l'atmosphère de Mars réside en la présence persistante d'une couche de poussière en suspension.SPICAM est un instrument embarqué à bord du satellite Mars-Express qui orbite autour de Mars depuis fin 2003. Il comprend deux modules: SPICAM/IR, un spectromètre infrarouge (1.0 - 1.7 µm) et SPICAM/UV, un spectromètre opérant dans le domaine ultraviolet (106 - 317 nm). Dans le cadre de ce travail, nous avons analysé les mesures de SPICAM/UV obtenues en visée nadir dans l'intervalle spectral s'étendant de 220 à 290 nm.L'analyse de ce domaine spectral permet d'étudier différentes espèces ou constituants de l'atmosphère martienne telles que l'ozone, les poussières ainsi que les nuages de glace. Dans le cadre de ce travail, nous avons développé une méthode capable d'inverser les spectres SPICAM/UV en visée nadir afin de restituer simultanément les quantités intégrées de ces différentes espèces, à savoir la colonne totale d'ozone ainsi que l'opacité intégrée des poussières et des nuages. Cette méthode est basée sur un code de transfert radiatif, permettant de tenir compte de la diffusion de la lumière par les particules en suspension dans l'atmosphère martienne. La réflectivité de la surface martienne est également étudiée et restituée pour les cas où aucun nuage n'est présent dans les scènes observées, les nuages réduisant la sensibilité en l'albédo de surface. Pour ce faire, un algorithme de détection des nuages a été développé et ses résultats ont été comparés avec les résultats obtenus par d'autres méthodes et instruments afin de le valider.Notre méthode d'inversion a été utilisée pour analyser les données recueillies par SPICAM/UV pendant plus de 4 années martiennes, permettant d'obtenir une climatologie des différentes espèces étudiées: des distributions spatiales et saisonnières de la colonne d'ozone, de l'opacité des poussières et nuages de glace ainsi que de l'albédo de surface sont présentées dans ce travail. Ces distributions sont discutées et comparées à celles obtenues dans des travaux antérieurs à l'aide d'autres instruments.Ce travail constitue également une préparation en vue de l'analyse des données de l'instrument NOMAD/UVIS, supervisé par l'IASB-BIRA, et qui sera lancé à bord de la sonde ExoMars Trace Gas Orbiter en direction de Mars au début de l'année 2016. L'algorithme développé dans ce travail a notamment été utilisé pour l'estimation de performances de NOMAD/UVIS telles que les limites de détection de certains gaz (O3, SO2 et NH3) ou encore les valeurs du rapport de signal-sur-bruit. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

L'ozone troposphérique est un gaz à effet de serre et un puissant oxydant qui impacte la santé et la production végétale. Afin d'analyser son impact sur le fonctionnement de la végétation il est nécessaire d'effectuer une partition entre le dépôt stomatique, qui pénètre à l'intérieur des feuilles, et le dépôt non stomatique, qui résulte de la destruction chimique de l'ozone sur les cuticules foliaires, le sol ou dans l'air à l'intérieur du couvert. L'objectif central de ce travail de thèse est d'améliorer la compréhension et la modélisation des processus impliqués dans le dépôt non stomatique d'ozone et plus particulièrement dans le dépôt sur les films d'eau à la surface des feuilles. Le modèle de transfert de masse et d'énergie sol-végétation-atmosphère MuSICA, capable d'estimer les quantités d'eau sur le feuillage à différents niveaux dans le couvert, a permis de modéliser la solubilisation puis la diffusion et réaction de l'ozone dans l'eau sur les feuilles. Cette voie de dépôt a permis d'expliquer les flux d'ozone observés sur blé en conditions humides en ajustant les valeurs du taux de réaction chimique de l'ozone dans le film d'eau de 103 s 1 en début de saison à 105 s 1 pendant la sénescence. Ce taux semble varier entre les espèces végétales (blé, hêtre et pin maritime) mais la tendance avec la sénescence persiste. Ces résultats ont été confortés par un dispositif expérimental original en laboratoire, sur blé, hêtre, pin blanc et chêne pédonculé. Des échanges de composés chimiques entre la feuille et le film d'eau réactifs avec l'ozone pourraient expliquer les ordres de grandeur obtenus et l'augmentation du taux de réaction en période de senescence. / Tropospheric ozone is a greenhouse gas but also a powerful oxidant that impacts vegetation health and productivity. In order to analyse the impact of ozone on vegetation functioning it is necessary to separate stomatal ozone deposition that penetrates inside the leaf interiors from non-stomatal deposition that result from ozone chemical destruction on leaf cuticles, in the soil or in the air inside the canopy. The central objective of this PhD work is to improve our understanding and modelling of the processes involved in non-stomatal ozone deposition and more specifically in ozone deposition on water films on leaf surfaces. For that purpose I used the soil-vegetation-atmosphere transfer model of mass and energy MuSICA. The choice of this model was motivated by its ability to estimate the quantities of water on foliage at different levels inside the canopy. This allowed me to model ozone dissolution, diffusion and reaction in the water film on wet leaves. This new deposition pathway could explain observed ozone fluxes over wheat in wet conditions by adjusting the chemical reaction rate of ozone in the water film from 103 s 1 at the beginning of the growing season, up to 105 s 1 during senescence. This reaction rate seemed to vary between species (wheat, beech, maritime pine) but the trend with the senescence remained. These results were then confirmed by lab experiments using an original setup, on wheat and beech, but also white pine and pedunculate oak. Exchanges of chemical compounds between the leaf and the water film that would react with ozone could explain the order of magnitude of the reaction rate and its increase during senescence.

Water quality changes that occur during establishment and maintenance of nitrification in two identical recirculating aquaculture systems containing rainbow trout are described. The time taken for the nitrification process to become established was 40-45 days. Mortality of fish attributed to elevated nitrite concentrations were recorded during the initial conditioning phase of the systems. Un-ionised ammonia concentrations did not attain lethal levels during this period. Nitrate concentrations accumulated slowly throughout the study, while the pH and alkalinity of the water decreased with progressive nitrification. Levels of carbon dioxide, calcium, dissolved and suspended solids remained relatively stable until the carrying capacity of the systems was increased, upon which they increased rapidly and general water quality deteriorated. Permanently elevated concentrations of ammonia and nitrite served as an indication that the carrying capacity of the systems had been exceeded. The use of ozone as a water enhancement treatment in aquaculture systems during one- and six-hour applications was also considered in this study. Ozonation significantly reduced nitrite levels at · low concentrations (0,1 - 0,15 mg/l), although they returned to pre-treatment levels within a few hours of cessation of the treatment. The formation of an unstable, intermediate product that reforms as nitrite in the absence of ozone, rather than the complete oxidation of nitrite to nitrate, is proposed. Ozonation also resulted in decreased dissolved solids, and improved the clarity and odour of the water. Ozone had no effect on ammonia concentrations (at pH > 7,0), or on nitrate or calcium levels, and did not conclusively increase the redox potential of the water. Residual ozone concentrations up to 0,04 mg/l in a sixhour treatment had no harmful effects on rainbow trout, and there were no signs of gas-bubble disease arising from supersaturation of the water with oxygen. Activated carbon filters were effective at removing residual ozone from the water after treatment. Treatment of the water with oxygen alone had no effect on nitrite concentrations.

Afin de mieux comprendre les processus responsables de la distribution de l'ozone (O3) dans la haute troposphère (UT) tropicale, cette thèse étudie différents aspects du transport de la pollution depuis les régions sources jusque dans l'UT. La première étude repose sur les observations spatiales IASI qui identifient un évènement de transport de masses d'air enrichies en O3 dans l'UT depuis l'Afrique vers l'Inde. Pour la saison de pré-mousson de tels enrichissement d'O3 dans l'UT au-dessus de l'Océan Indien sont essentiellement attribués à des intrusions stratosphériques. Afin de déterminer son origine des simulations ont été effectuées permettant d'exclure une origine stratosphérique et montrent l'impact prépondérant des NOx produit par les éclairs (LiNOx) en Afrique pour expliquer cet enrichissement d'O3. Cette étude pourra être étendue à d'autres saisons, pour consolider les conclusions obtenues dans le cadre du projet INDOEX. La deuxième partie porte sur l'étude de l'impact d'un système convectif très profond sur la composition de l'UT pendant la mousson asiatique d'été. La simulation avec un traceur passif montre la capacité du système situé le long de l'Himalaya centrale à soulever des masses d'air polluées jusqu'à 100 hPa, altitudes auxquelles la pollution est transportée rapidement par la circulation de l'anticyclone de la mousson asiatique. Confirmant le conduit privilégié de transport vers l'UTLS identifié par Bergman et al. 2013. Cependant l'activation du schéma chimique montre une surestimation des LiNOx produites, un ajustement de leur paramétrisation devra être effectué ainsi que des simulations de sensibilité pour correctement quantifier la production d'O3. Ce travail prend place dans des problématiques actuellement au centre d'une collaboration internationale, ACAM (Atmospheric Composition and the Asian Monsoon) visant à étudier les interactions complexes de la mousson asiatique d'été entre dynamique et chimie, jusqu'à l'échelle du changement climatique. / To better understand the processes controling for the distribution of upper tropospheric (UT) ozone (O3) in the tropics, this thesis examines different aspects of pollution transport from sources regions to UT level, through two case studies that take place in the still debated issues.. First study is based on IASI space observations identified an event of transport of UT enriched O3 air masses from Africa to India. During the pre-monsoon season, events of O3 enrichment in UT above the Indian Ocean were essentially attributed to stratospherics intrusions. Simulations have been used to determine its origin, it excludes a stratospheric origin for the event and indicates a probable important contribution by lightning (LiNOx) that occurs over Africa regions. This study could be extended to the whole region and other seasons with a focus on the spring season in order to complete the conclusions obtained during the INDOEX program. The second part focuses on the characterisation of the impact of a deep convective system upon the UTLS composition during the asian summer monsoon. Simulation with a passive tracer highlights the potential of the convective system located over the central Himalaya foothills, to uplift polluted air masses in UTLS to 100 hPa, where the pollutants are rapidly transported by the asian monsoon anticyclone circulation. In agreement with transport pipe towards the UTLS identified by Bergman et al. 2013. However simulation including reactive chemistry show an overestimation by the model of the amount of LiNOx produced, so an adjustment of their parameterization must be made and sensitivity analysis are foreseen to determine precisely O3 production. This study is established in connection with actual major problematic at the center of general debate of the international collaboration. Like ACAM (Atmospheric Composition and the Asian Monsoon) whose targeting the complexe interaction of asian summer monsoon to atmospheric dynamics and chemistry, as well as climate change impact.